Problem: $-5\dfrac{1}{2} \div \left(-4\dfrac{1}{2}\right) = $
Answer: Let's start by converting the mixed numbers to fractions. $\phantom{=}-5\dfrac{1}{2} \div \left(-4\dfrac{1}{2}\right)$ $= -\dfrac{11}{2}\div\left(-\dfrac{9}{2}\right)$ $= -\dfrac{11}{2}\cdot\left(-\dfrac{2}{9}\right)~~~~~~~\text{multiply by the reciprocal}$ $=-\dfrac{11}{{1}\cancel{2}}\cdot \left(- \dfrac{{1}\cancel{2}}{9}\right)$ $=-\dfrac{11}{{1}}\cdot \left(- \dfrac{{1}}{9}\right)$ $=\dfrac{11}{9}\text{ or }1\dfrac29$